Re: [Discuss-gnuradio] Need help identifying jammer signal

[Juha Vierinen]

Last Friday we managed to finally track this thing down. It was a broken FSK telemetry system on an FM radio tower. It was about 30 km Southwest of our radar.

I did a small write up about this:

http://kaira.sgo.fi/2013/12/perfect-incoherent-scatter-radar-jammer.html

Thanks for all the help. 

juha

On Wed, Dec 11, 2013 at 4:34 PM, Johnathan Corgan <address@hidden> wrote:

On 12/10/2013 02:00 PM, Miki Lustig - KK6GEO wrote:

> These look like 2pi jumps -- which is the an artifact if the
> unwrapping is not working well.

Sure, I see what you mean.

Backing up and just plotting the unwrapped phase, you can see in the
first image that overall it is increasing at one rate, then shifts to a
lower rate about 1.5 seconds into the file.

The finer structure is much more interesting.  The second image shows
the phase making fast jumps every 500 samples (10 ms), with periods of
oscillation in between.  The detail on this is in image 3.

I still have no idea what this is, but it sort of looks like an
oscillator that is disciplined at 100 Hz.

--
Johnathan Corgan, Corgan Labs
SDR Training and Development Services
http://corganlabs.com